“Hey @united – never flying on your airline again,” she wrote. “Know I’m not the only one. Your statement is abhorrently vague & without accountability.”

The drama prompting the outcry took place on the tarmac at an airport in Chicago, Illinois, where passengers learned staff had overbooked the flight to Kentucky and four volunteers had to give up their seats for United employees who had to be in Louisville on Monday.

When no one volunteered four people were chosen by the computer at random and three of them left the plane. The fourth, a doctor, refused to get off and staff were forced to call airport police, who ripped the man out of his seat, banging his head in the process.

In video of the disturbing incident posted online by an outraged passenger, the bloodied doctor can he heard howling in pain as cops drag him down the aisle by his arms.

“We followed the right procedures,” United spokesman Charlie Hobart told the Associated Press. “That plane had to depart. We wanted to get our customers to their destinations, and when one gentleman refused to get off the aircraft, we had to call the Chicago Police Department.”

An official statement reads: “Flight 3411 from Chicago to Louisville was overbooked. After our team looked for volunteers, one customer refused to leave the aircraft voluntarily and law enforcement was asked to come to the gate. We apologize for the overbook situation. Further details on the removed customer should be directed to authorities.”

Getting on a United flight this morning. Excited to, I don't know… stay on?

Filmmaker Joss Whedon boarded a United flight on Monday as the news broke, and sarcastically admitted he felt lucky to be on board, joking: “Getting on a United flight this morning. Excited to, I don’t know… stay on?”

He added: “For the comfort and safety of the other passengers, please remember we will be resorting to cannibalism BY GROUP NUMBER.”

Having flown #united last week, I feel very blessed to not be tweeting this message from a hospital bed.